Zinc and copper in preterm neonates: relationship with breast milk

The study was conducted to assess copper and zinc levels in neonate's serum, mother's serum, neonate's hair and urine and to ascertain association between them. It is of concern whether zinc and copper deficiency is present at birth and maternal blood and breast milk zinc and copper levels have any effect on this. The study sample included 155 neonates with gestational age 26-41 wks and birth weight 0.550-3.800 kg. Mother's serum, breast milk, neonate's serum, hair, urine samples were analysed for zinc and copper by atomic absorption spectrophotometry. Gestational age was estimated either singly or by combination of date of last normal menses, fetal ultrasonography, and postnatal measures of physical and neurological development by clinical examination and weight by Secca electronic balance. The neonates were classified into term and preterm, small (SGA) and appropriate for gestational age (AGA). Neonates over 37 wks and 2.5 kg served as controls. To assess the dependency, relationship and effectiveness of quantitative predictive variables on the predictions of values, multiple regression analysis was used. Neonates between 26-30 wks gestational age and < 2.5 kg birth weight had significantly low serum zinc and copper. Breast milk zinc was low in mothers delivering preterm and < 2.5 kg neonates. Urinary copper and zinc levels were high in preterm appropriate for gestational age (Pre AGA) than term neonates. Multiple regression analysis revealed that neonate's serum Cu, serum Zn, hair Cu, hair Zn, urine Cu and urine Zn had contribution variability of 49.8%, 51.8%, 49.2%, 16.6%, 52.2% and 68.9%, respectively. The effect of mother's serum, breast milk, and neonate's serum copper and zinc collectively was significant for serum copper (F = 29.59) and hair zinc (F = 32.03). Preterm and low birth weight infants during subsequent growth and development should be supplemented with zinc and copper when on breast feeding.

Involvement of the N-terminus of Kir6.2 in the inhibition of the KATP channel by ATP

1. ATP-sensitive potassium (KATP) channels are composed of pore-forming Kir6.2 and regulatory SUR subunits. A truncated isoform of Kir6.2, Kir6.2DeltaC26, expresses ATP-sensitive channels in the absence of SUR1, suggesting the ATP-inhibitory site lies on the Kir6. 2 subunit. 2. We examined the effect on the channel ATP sensitivity of mutating the arginine residue at position 50 (R50) in the N-terminus of Kir6.2, by recording macroscopic currents in membrane patches excised from Xenopus oocytes expressing wild-type or mutant Kir6.2DeltaC26. 3. Substitution of R50 by serine, alanine or glycine reduced the Ki for ATP inhibition from 117 microM to 800 microM, 1.1 mM and 3.8 mM, respectively. The single-channel conductance and kinetics were unaffected by any of these mutations. Mutation to glutamate, lysine, asparagine, glutamine or leucine had a smaller effect (Ki, approximately 300-400 microM). The results indicate that the side chain of the arginine residue at position 50 is unlikely to contribute directly to the binding site for ATP, and suggest it may affect ATP inhibition by allosteric interactions. 4. Mutation of the isoleucine residue at position 49 to glycine (I49G) reduced the channel ATP sensitivity, while the mutation of the glutamate residue at position 51 to glycine (E51G) did not. 5. When a mutation in the N-terminus of Kir6.2DeltaC26 that alters ATP sensitivity (R50S; Ki, 800 microM) was combined with one in the C-terminus (E179Q; Ki, 300 microM), the Ki for the apparent ATP sensitivity was increased to 2.8 mM. The Hill coefficient was also increased. This suggests that the N- and C-termini of Kir6.2 may co-operate to influence channel closure by ATP.

Effects of vitamin A on growth of vitamin A-deficient children: field studies in Nepal

Inconsistencies have been observed in the impact of vitamin A (VA) supplementation on early child growth. To help clarify this issue, a cohort of 3377 rural Nepalese, nonxerophthalmic children 12-60 mo of age were randomized by ward to receive vitamin A [60,000 microg retinol equivalents (RE)] or placebo-control (300 RE) supplementation once every 4 mo and followed for 16 mo. VA had no impact on annual weight gain or linear growth. However, arm circumference (AC) and muscle area (MA) growth improved in VA recipients, by 0.13 cm and 25 mm2, respectively, over controls. Growth of children with xerophthalmia, who were treated with >/= 120, 000 RE at base line, was also compared to that of nonxerophthalmic children, stratified by initial wasting status, and adjusted for sex, baseline age and measurement status. Among initially nonwasted children (AC >/= 13.5 cm), VA-treated xerophthalmic children (n = 86) gained 0.7 cm more in linear growth than nonxerophthalmic children. Among initially wasted children (AC < 13.5 cm), VA-treated children (n = 34) gained additional weight (672 g), height (approximately 1 cm), muscle (76 mm2) and fat (79 mm2) areas, and subscapular skinfold (1.3 mm) compared to changes observed in nonxerophthalmic children. Relative increments in soft tissue growth occurred within 4 mo of VA treatment, while the effect on linear growth was gradual. Moderate-to-severe VA deficiency, marked by xerophthalmia, is likely to impair normal physical growth, but milder stages of deficiency may not have this effect in rural South Asia.

Mortality of infants < 6 mo of age supplemented with vitamin A: a randomized, double-masked trial in Nepal

The effect of supplementing 11,918 infants < 1 mo and 1-5 mo of age with vitamin A (15,000 and 30,000 micrograms retinol equivalents or 50,000 and 100,000 IU, respectively) or a placebo on subsequent 4-mo mortality was assessed in a randomized, double-masked community trial in the rural plains of Nepal. There were 130 deaths (51.6/1000 child-y) in the control group and 150 deaths (57.1/1000 child-y) in the vitamin A group, yielding a relative risk of 1.11 (95% CI: 0.86, 1.42), which is indicative of no overall effect on early infant mortality. There was a tendency for the relative risk of mortality among vitamin A recipients to rise with improved nutritional status. These results suggest that distribution of a large oral dose of vitamin A to infants < 5-6 mo of age may not benefit short-term survival. This is in contrast with the results of trials in which older infants and children in this same population were supplemented.

Tolerance of young infants to a single, large dose of vitamin A: a randomized community trial in Nepal

A randomized, double-masked trial was carried out in rural Nepal to investigate the incidence and severity of acute side-effects among neonates ( < 1 month of age) and infants aged 1-6 months who received a large, oral dose of vitamin A (15,000 retinol equivalents (RE) (50,000 IU) and 30,000 RE (100,000 IU), respectively) or placebo (75 RE (250 IU) and 150 RE (500 IU), respectively) in oil. Infants (vitamin A group, n = 1461; controls, n = 1379) were assessed for vomiting, loose stools, fever, and irritability during the 24 hours before and after dosing. Fontanelles were palpated 24 hours after dosing. Neonates exhibited no excess risk of adverse side-effects after receiving 15,000 RE. Compared with controls the older infants who ingested 30,000 RE had a 1.6% excess rate of vomiting (95% confidence interval (CI): 0.2-3.0%) and a 0.5% excess rate (95% CI: -0.1 to 1.1%) in the occurrence of bulging fontanelles. There were no other significant differences in the older infants. The controlled, periodic distribution of a single 15,000 RE dose of vitamin A therefore confers no apparent acute risk to young infants; a 30,000 RE dose is associated with a minimum risk of transient, acute side-effects.

Antimicrobial susceptibility pattern and serotyping of Streptococcus pneumoniae isolated from Kanti Children Hospital in Nepal

Background: Invasive pneumococcal disease is a significant cause of morbidity and mortality worldwide and it is a major cause for childhood deaths in Nepal. Objectives: The aim of this study was to establish the antimicrobial susceptibility pattern of Streptococcus pneumoniae and perform serotype responsible for pneumococcal disease in Nepal. Materials and methods: All together 3774 children from 2 to 60 months who fulfilled the enrollment criteria for suspect of bacterial pneumonia, sepsis or meningitis were enrolled for etiologic studies of severe illness. During the study period 60 isolates of Streptococcus pneumoniae were isolated and the antimicrobial susceptibility testing and serotyping were performed. Results: The study showed that 24 (52.17%) isolates were resistant to Cotrimoxazole, 3 (6.5%) isolates were intermediately resistant to Penicillin but no Penicillin resistant strains were isolated. The 1 (2.17%) isolate was recorded as Erythromycin and Chloramphenicol resistant and only 1 (2.17%) isolate was found intermediately resistant to Cefotaxime. Of the 60 isolates, serotyping result was available only for 46 isolates. The most common serotypes were serotype 1 (27. 65%) followed by serotype 5 (19.14%) and serotype 4 (8. 5%) respectively followed by serotype 39, 23F, 7F, 19B, 12A, 14, 18F, 6B, 32, 16, 19F and 25F. Conclusions: Alarming level of Cotrimoxazole resistance demands revision of pneumonia treatment policy in Nepal and rising tendency of other drug resistance against Streptococcus pneumoniae showed use of these drugs for the treatment of meningitis, pneumonia and other serious infections needs extended research. The common serotype 1, 5 and 4 need to be incorporated in pneumococcal vaccine to immunise children in Nepal. Key words: Antimicrobial susceptibility; Streptococcus pneumoniae; Serotyping; Nepal DOI: 10.3126/kumj.v8i2.3551 Kathmandu University Medical Journal (2010), Vol. 8, No. 2, Issue 30, 164-168